diff --git a/populate_build.py b/populate_build.py
index 2e78e13..37ad0d9 100755
--- a/populate_build.py
+++ b/populate_build.py
@@ -310,7 +310,7 @@ def get_new_images(
 def parse_denylist(filename: Path) -> List[str]:
     """Parse the list of images to skip."""
     with filename.open() as handle:
-        return [entry for line in handle.readlines() if (entry := line.strip() and not line.startswith('#'))]
+        return [entry for line in handle.readlines() if (entry := line.strip()) and not line.startswith('#')]
 
 
 def generate_build_script(filename: Path, images: List[str]) -> None: